To better enable debug of u-boot itself (in particular SPL). To debug u-boot you want to put your board in JTAG boot mode for quick recompile and elf downloads via the JTAG debugger. Yet you may still want to boot from a persistent storage media (SD or QSPI). Allow override of the boot mode pins to facilitate this.
Signed-off-by: Peter Crosthwaite crosthwaite.peter@gmail.com --- arch/arm/cpu/armv7/zynq/slcr.c | 4 ++++ doc/README.zynq | 6 ++++++ 2 files changed, 10 insertions(+)
diff --git a/arch/arm/cpu/armv7/zynq/slcr.c b/arch/arm/cpu/armv7/zynq/slcr.c index 934ccc3..26e02b8 100644 --- a/arch/arm/cpu/armv7/zynq/slcr.c +++ b/arch/arm/cpu/armv7/zynq/slcr.c @@ -155,8 +155,12 @@ void zynq_slcr_devcfg_enable(void)
u32 zynq_slcr_get_boot_mode(void) { +#ifdef CONFIG_ZYNQ_BM_FORCE + return CONFIG_ZYNQ_BM_FORCE; +#else /* Get the bootmode register value */ return readl(&slcr_base->boot_mode); +#endif }
u32 zynq_slcr_get_idcode(void) diff --git a/doc/README.zynq b/doc/README.zynq index 043c970..70be7ae 100644 --- a/doc/README.zynq +++ b/doc/README.zynq @@ -52,6 +52,12 @@ board_late_init() will read the bootmode values using slcr bootmode register at runtime and assign the modeboot variable to specific bootmode string which is intern used in autoboot.
+This value can be overridden at compile time with the define +CONFIG_ZYNQ_BM_FORCE. This is useful for debugging a u-boot elf downloaded +over JTAG. E.g. The board will be jumpered for ZYNQ_BM_JTAG, but you can +force u-boot to attempt an SD or QSPI boot should that be what you want to +debug. + SLCR bootmode register Bit[3:0] values #define ZYNQ_BM_NOR 0x02 #define ZYNQ_BM_SD 0x05